Class I, II and III

Question 1

Describe a skeletal class I relationship:

Answer 1

Mandible 2-3mm posterior to maxilla

Question 2

Describe a skeletal class II relationship:

Answer 2

Mandible retruded relative to maxilla

Question 3

Describe a skeletal class III relationship:

Answer 3

Mandible protruded relative to maxilla

Question 4

What is the frankfort plane?

Answer 4

The uppermost point of external auditory meatus to the lowest point of the orbital rim

Question 5

What is the mandibular plane?

Answer 5

The lowest boarder of the mandible

Question 6

What is a Class I canine relationship?

Answer 6

The cusp tip of upper canine rests adjacent to interproximal surfaces of lower canine & 1st premolar

Question 7

Describe class I incisor relationship:

Answer 7

The lower incisor edges occlude with or lie immediately below the cingulum plateau of the upper central incisors

Question 8

Explain what a Class II incisor relationship; Division 1 and Division 2 are:

Answer 8

Class II incisor relationship = lower incisor edges lie posterior to cingulum plateau of upper incisors

Division 1: increased overjet with upper centrals usually proclined

Division 2: upper centrals retroclined and laterals proclined

Question 9

Describe the class II molar & canine relationships:

Answer 9

The upper molar and canine cusp tip are further forward relative to the lower arch

Question 10

What habit is related to class II division 1 occlusion?

Answer 10

Thumb-sucking

Question 11

Define overjet:

Answer 11

The horizontal overlap of the maxillary central incisors over the mandibular central incisors

Question 12

What is the different between a complete and incomplete overbite?

Answer 12

Complete = lower incisors in contact with hard tissues

Incomplete = lower incisors in contact with soft tissues

Question 13

Define crossbites:

Answer 13

Crossbite is a lateral misalignment of the dental arches